Born in Assam, India, she was a pop icon of the "swinging London" era of the 1960s. She made her feature film debut in The Fast Lady, a 1962 romantic comedy. She also appeared in critically acclaimed films such as Doctor Zhivago (1965), Darling (1965), for which she won the Academy Award for Best Actress, and Nicolas Roeg's Don't Look Now with Donald Sutherland.

In 1996, she appeared as Gertrude in Kenneth Branagh's film adaption of Hamlet.